SAP ABAP 將負數的符號移到左邊

DATA GV_STR TYPE STRING.

CLEAR:GV_STR.

GV_STR = GS_HEAD-WRBTR_FRE.
IF GS_HEAD-WRBTR_FRE < 0.
CALL FUNCTION 'CLOI_PUT_SIGN_IN_FRONT'
  CHANGING
    VALUE         = GV_STR.
ENDIF.